Knitting machine



L. BAUMBER March 22, 1955 'l Hlllllllllll United States Patent Office 2,704,445 Patented Mar. 22, 1955 KNITTING MACHINE Application September 2, 1953, Serial No. 378,131

Claims priority, application New Zealand September 11, 1952 1 Claim. (Cl. 66-163) This invention relates to knitting machines especially of the multi-wrap thread type in which many wrap threads pass into the machine for the knitting of an article of clothing or the like therefrom. An object of the present invention is to provide additional mechanism on such machines which will automatically stop their operation in the event of any one (or more) of the multiplicity of threads having a large knot, a slub or other foreign body thereon which if passed into the machine, would cause or tend to cause the production of a defective article.

Knitting machines of the kind referred to above will consistently produce satisfactory articles of clothing and the like provided the wrap threads or yarns from which the articles are made are of good uniform quality, but if large knots, slubs and foreign bodies are encountered from time to time in these threads or yarns, such knots, slubs and foreign bodies, on passage into the machine, can cause resistance to their free travel and present other difficulties to the proper operation of the machines which may cause the production of numerous defective articles before being noticed, considerable work and lost production being caused in getting the machine back into operation.

With these automatic machines it is not practicable to maintain a watch on the threads passing into same and thus numbers of inferior articles can be produced before the defect is noticed, the invention having been devised to ensure that in the event of any thread having any form of enlargement such as a large knot, slub or the like the passage of which into the machine is undesirable, automatic stopping of the machine will result, thus enabling the operator to remove the enlargement and obtain the consistent production of the articles substantially without defect.

Broadly the invention comprises improvements in or relating to knitting machines wherein a thread or threads on passage from the thread bobbin gallery into the knitting portion of the machine pass through a thread hole or thread holes in floating plate means, any obstruction on the thread or threads which prevent passage through the hole or holes of said floating plate means causing a movement of said floating plate which completes an electric circuit for effecting stopping of the operation of the machine.

In describing the invention reference will be made to the accompanying drawing in which:

Figure I shows an elevation of the improved mechanism as applied to a knitting machine,

Figure 2 is a sectional view on line AB of Fig. 1, and

Figure 3 is an enlarged sectional view through a rod and the slip ring and floating plate mounted thereon.

The mechanism embodying this invention is added to the knitting machine in the space which is directly under the thread bobbin carrier or gallery 1 thereof, through which space the multiplicity of threads 2 pass downwardly to enter the main portion of the machine in which the knitting is effected, these threads 2 being readily visible until their entry to the machine (not shown). Existing rods 3 which may be three in number are vertically disposed between the bottom of the bobbin gallery 1 and the top of the machine where the threads 2 enter the latter, these rods 3 being disposed on a circle which is concentric with the vertical centre line of the machine.

On these existing rods 3, the mechanism embodying this invention is mounted, and is seen to include a metal slip ring 4 which is secured to the rods 3 and disposed concentrically with the machine. The ring 4 is substantially flat and has a large central hole 5, such slip ring 4 being insulated from the rods 3 by insulating material bushes 6 and upper and lower insulating washers 7 and 7a or the bite to keep it from metallic contact with the rods 3 which pass through the ring 4 near its periphery and which support the latter, for example, by hearing of the ring on collars or the like 8 secured to the rods 3 under the slip ring 4 (Fig. 3).

Secured to the slip ring 4 are contacts 9, which may be three in number, these being of pin form and extending upward from the ring 4 at evenly spaced apart intervals around the latter, such as, in between the three rods 3.

An electric brush contact 10 or other form of electrical connection is made to this slip ring 4 and is connected by wire 11 to electric switch mechanism hereinafter referred to.

Also mounted on the rods 3 and disposed directly above the slip ring 4 there is a floating plate 12, this being of thin metal and circular in shape with clearance holes 12a being provided near its periphery through which the rods 3 pass so that the plate 12 is free for vertical movement on such rods 3. Light compression springs 13 are disposed on the rods 3 between the slip ring 4 and the floating plate 12 for yieldingly holding the plate 12 upward against collars 14 secured on the rods 3, the floating plate 12 and springs 13 making metallic contact with the rods 3, but being insulated from the slip ring 4 by the bottoms of the springs 13 bearing on the insulating washers 7a, so that the tops of the contacts 9 of the slip ring 4 are just clear of the bottom of the floating plate 12.

Drilled through this floating plate 12 in concentric circles near its centre there are small thread holes 15, the size of these holes 15 being small enough to stop knots or other obstructions on the threads 2 from passing therethrough but large enough to enable the threads 2 to freely pass therethrough.

The electric brush contact 10 of the slip ring 4 is connected by insulated wire 11 to a known form of electric switch or relay mechanism (not shown) which will be grounded to the machine, this mechanism in known manner switching off the electric current to the electric motor which drives the knitting machine on the completion of an electric circuit between the floating plate 12 and the contacts 9 of the slip ring 4.

In setting up the machine for operation, the numerous wrap threads or yarns 2 from the bobbin gallery 1 are each passed through a thread hole 15 in the floating plate 12, and then through the large hole 5 in the slip ring 4 clear of the latter, after which the threads or yarns pass into the top of the knitting portion of the machine.

With such machine in normal operation, the threads 2 all freely travel down through their respective holes 15 in the floating plate 12 which remains in the upward position bearing against the collars 14 on the rods 3, these threads 2 being all pulled in downward direction from their respective bobbins on the gallery 1 by the knitting operation taking place in the machine, the passage of the threads 2 not causing sufficient pull on the floating plate 12 to move same downward against the resistance to such movement as caused by the compression springs 13.

In the event however of any one thread 2 having a large knot, slub or the like thereon which is so large as to be unable to pass through the related thread hole 15 in the floating plate 12, the pull on the thread 2 caused by the knitting machine will cause the floating plate 12 to be displaced downward and plate 12 will come into contact with a contact or contacts 9 of the slip ring 4 and thus an electric circuit will be completed to the electric switch or relay mechanism which immediately releases the clutch on the machine or switches off the electric motor and thereby stops operation of the knitting machine.

An enlarged knot may be placed by the spool winder on the thread 2 of a spool or bobbin just before the end of such thread, so that just before the spool runs out of thread, the apparatus embodying this invention will be brought into operation.

The electric apparatus may include (if so desired) any known form of electrically actuated warning or indicator apparatus whereby visual or audible warning is given that the machine has stopped. Then the machine attendant who may be in charge of quite a number of the machines, can inspect the threads 2 directly above the floating plate 12 and on noticing the thread which has the obstruction thereon, remove such obstruction or if necessary break the thread and retie the latter with a knot which is within normal limits as to size so that it can pass through the plate 12, this removal of the obstruction permitting the floating plate 12 to return to normal position against the collars 14 in which position it is clear of the slip ring contacts 9.

Thus the machine can be re-started and its operation continued in the production of an article free from the defects which would otherwise have occurred if the obstruction had been permitted to pass into the knitting portion of machine.

While the invention has been described with particular reference to an illustrative embodiment thereof, it is to be understood that the invention is not limited to that particular embodiment, and that various changes and modifications may be elfected in the latter without departing from the scope or spirit of the invention as defined in the appended claim.

I claim:

An attachment for a multiple-thread knitting machine having a thread bobbin carrier disposed above the top of the machine; said attachment comprising rods disposed between the top of the knitting machine and said thread bobbin carrier, slip ring means secured to said rods below the bobbin carrier and having an opening therein through which all of the threads pass from the bobbin carrier to the top of the knitting machine, means electrically insulating said slip ring means from said rods, contacts carried by said slip ring means and extending upwardly from the latter, an electrical connection to said slip ring means for controlling the drive circuit of the knitting machine, floating plate means mounted on said rods directly above said slip ring means and being freely movable vertically on said rods, stop means on said rods for limiting the upward movement of said floating plate means at a position where the latter is spaced from said contacts, spring means on said rods for yieldably holding said floating plate means against said stop means, said floating plate means having a series of holes therein each adapted to have a related thread pass therethrough between the thread bobbin and the top of the knitting machine so that, when an enlargement occurs on one of the threads which would cause defective knitting, such enlargement; engages said floating plate means and moves the latter against said contacts to complete an electrical circuit for stopping the operation of the knitting machine.

References Cited in the file of this patent UNITED STATES PATENTS 424,295 Haslam Mar. 25, 1890 FOREIGN PATENTS 106,380 Great Britain May 24, 1917 

